A massive 12TB archive of old Steam2 content has surfaced online, apparently containing nearly every version of games uploaded to Valve's servers between 2003 and 2013, including unreleased prototypes, playtest builds, and cut content. Early discoveries include deleted Portal 2 material, files tied to Half-Life 2: Episode 3, and beta builds of games like Left 4 Dead 2, CS: GO, Spore, and Dragon Age: Origins. Researchers claim much of the material was once accessible through an unsecured public API. Ars Technica reports: The reason this weekend's leaked content cuts off abruptly in 2013 is because that's when Valve updated its content distribution system from "Steam2" to the current SteamPipe...